skyyws fb6d96e001 IMPALA-9741: Support querying Iceberg table by impala ...

This patch mainly realizes the querying of iceberg table through impala,
we can use the following sql to create an external iceberg table:
    CREATE EXTERNAL TABLE default.iceberg_test (
        level string,
        event_time timestamp,
        message string,
    )
    STORED AS ICEBERG
    LOCATION 'hdfs://xxx'
    TBLPROPERTIES ('iceberg_file_format'='parquet');
Or just including table name and location like this:
    CREATE EXTERNAL TABLE default.iceberg_test
    STORED AS ICEBERG
    LOCATION 'hdfs://xxx'
    TBLPROPERTIES ('iceberg_file_format'='parquet');
'iceberg_file_format' is the file format in iceberg, currently only
support PARQUET, other format would be supported in the future. And
if you don't specify this property in your SQL, default file format
is PARQUET.

We achieved this function by treating the iceberg table as normal
unpartitioned hdfs table. When querying iceberg table, we pushdown
partition column predicates to iceberg to decide which data files
need to be scanned, and then transfer this information to BE to
do the real scan operation.

Testing:
- Unit test for Iceberg in FileMetadataLoaderTest
- Create table tests in functional_schema_template.sql
- Iceberg table query test in test_scanners.py

Change-Id: I856cfee4f3397d1a89cf17650e8d4fbfe1f2b006
Reviewed-on: http://gerrit.cloudera.org:8080/16143
Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>

2020-09-06 02:12:07 +00:00

..

functional_schema_template.sql

IMPALA-9741: Support querying Iceberg table by impala

2020-09-06 02:12:07 +00:00

schema_constraints.csv

IMPALA-9741: Support querying Iceberg table by impala

2020-09-06 02:12:07 +00:00